Description

To determine the surface tension of a liquid using the method of a horizontal wire suspended from a precision balance beam. Vertical rod with adjustable height and clamp mechanism mounted on triangular heavy base with Precision lever arm with pointer and scale for deflection reading fitted with a movable rider for fine adjustment and balance calibration made from nickel-plated brass with lightweight pan suspended by fine wire from the beam used to hold standard weights or add tension for measurement. Vertical millimeter scale attached for pointer movement and mirror provided behind the pointer for parallax-free readings. Levelling screw fitted on one foot of base. Supplied with calibrated weights ranging from 1mg to 10mg.

Working Principle: 

• Based on balancing the vertical component of surface tension force with known weights on the pan.
• Surface tension T=W2LT = frac{W}{2L}T=2LW?, where:
  • WWW = weight added to detach the ring/wire
  • LLL = length of wire in contact with the liquid